RESUMO
Background: Coronary artery bypass grafting (CABG) is a well-established surgical procedure used to treat significant coronary artery disease. Nevertheless, unfavorable cardiovascular events and complications, including cardiac arrhythmias may be observed in patients after CABG. Previous studies have revealed a relationship between risk of cardiac arrhythmias and abnormal heart rate variability (HRV), which reflects adverse alterations in cardiac autonomic functioning, that may occur in patients after a CABG procedure. The aim of this article was to provide a systematic review of the major research findings in this area. Methods: A literature search was carried out using PubMed, Cochrane, and Embase databases and relevant articles, published in English, were analyzed in detail. Results: Studies performed so far have shown time depending changes in HRV after CABG. Time and frequency domain HRV decrease acutely after CABG but recover almost completely to pre-operative values by 6 months after surgery. Some preoperative clinical states such as: heart failure, type 2 diabetes mellitus and depression adversely affect post-CABG HRV. Finally, post-CABG cardiac rehabilitation appears to improve exercise capacity and speed up recovery of HRV. Conclusions: Generally, traditional time and frequency domain HRV parameters fail to predict complications post-CABG. Altered non-linear measures of HRV may identify subgroups of subjects at increased risk of potential complications, including atrial fibrillation post-CABG. However, data available currently does not appear to unequivocally support the hypothesis that early HRV assessment in post-CABG patients predicts long-term mortality.
RESUMO
We aimed to identify prevalence and association of comorbid chronic kidney disease (CKD), acute kidney injury (AKI) and utilization prevalence of continuous renal replacement therapy (CRRT) in COVID-19-hospitalized patients as a function of severity status. With the ongoing struggle across the globe to combat COVID-19 disease, published literature has described the role of kidney disease in COVID-19 patients based on single/multicenter experiences across the globe. We extracted data from observational studies describing comorbid CKD, AKI and CRRT and outcomes and severity of COVID-19-hospitalized patients from December 1, 2019-August 20, 2020 following PRISMA guidelines. Severity of COVID-19 includes intensive care unit admission, oxygen saturation < 90%, invasive mechanical ventilation utilization, in-hospital admission and mortality. Meta-analysis was performed using a random-effects model to calculate pooled estimates, and forest plots were created. In total, 29 studies with 15,017 confirmed COVID-19 patients were included. The overall prevalence of AKI was 11.6% [(430/3693)], comorbid CKD 9.7% [(1342/13,728)] and CRRT 2.58% [(102/3946)] in our meta-analysis. We also found higher odds of comorbid CKD (pooled OR: 1.70; 95%CI: 1.21-2.40; p = 0.002), AKI (8.28; 4.42-15.52; p < 0.00001) and utilization of CRRT (16.90; 9.00-31.74; p < 0.00001) in patients with severe COVID-19 disease. Conclusion Our meta-analysis suggests that comorbid CKD, AKI and utilization of CRRT were significantly associated with COVID-19 disease severity. Clinicians should focus on early triaging of COVID-19 patients with comorbid CKD and at risk for AKI to prevent complication and mortality.